In the field of confectionery, products are known which are made from chocolate or other lipid-based material and have a two-piece structure. For example, a shell can be produced first, filled with an appropriate filling such as fruit puree, liquor or caramel and closed with a lid. Other confectionery products, both filled and hollow, require two lipid-based moulded parts to be joined together around their perimeters.
U.S. Pat. No. 3,962,473 describes a method of making crust liqueurs, in which liquid filling is deposited in chocolate shells, which are closed by pouring liquid chocolate so as to produce a lid. As far as the bonding between the lid and the shell is concerned, the described method relies on the bond between the molten and, therefore, warm chocolate which is poured to produce the lid, and the edge of the shell, which is generally cold.
In this regard, DE 3444060 A1 describes a method and apparatus, in which a filled confectionery product is produced by forming a shell and filling same. Afterwards, the shell is passed through a heating station to heat the edges of the shell before the lid is applied by pouring molten chocolate on the shell and the filling. Experiments have shown that the bonding strength of products made in the aforementioned way is sometimes insufficient.